Vapochromic behaviour of porous crystals is beneficial for facile and rapid detection of gaseous molecules without electricity. Toward this end, tailored molecular designs have been established for metal–organic, covalent-bonded and hydrogen-bonded frameworks. Here, we explore the hydrochromic chemistry of a van der Waals (VDW) porous crystal. The VDW porous crystal VPC-1 is formed from a novel aromatic dendrimer having a dibenzophenazine core and multibranched carbazole dendrons. Although the constituent molecules are connected via VDW forces, VPC-1 maintains its structural integrity even after desolvation. VPC-1 exhibits reversible colour changes upon uptake/release of water molecules due to the charge transfer character of the constituent dendrimer. Detailed structural analyses reveal that the outermost carbazole units alone are mobile in the crystal and twist simultaneously in response to water vapour. Thermodynamic analysis suggests that the sigmoidal water sorption is induced by the affinity alternation of the pore surface from hydrophobic to hydrophilic.

多孔晶体的 Vapochromic 行为有利于在没有电的情况下轻松快速地检测气体分子。为此，已经为金属有机、共价键和氢键框架建立了定制的分子设计。在这里，我们探索了范德华 (VDW) 多孔晶体的水致变色化学。VDW 多孔晶体VPC-1由具有二苯并吩嗪核和多支化咔唑树枝状结构的新型芳香族树枝状聚合物形成。尽管组成分子通过 VDW 力连接，但VPC-1即使在去溶剂化后仍能保持其结构完整性。VPC-1由于构成树枝状聚合物的电荷转移特性，在吸收/释放水分子时表现出可逆的颜色变化。详细的结构分析表明，最外层的咔唑单元单独在晶体中移动，并同时响应水蒸气而扭曲。热力学分析表明，S 形吸水是由孔表面从疏水到亲水的亲和力交替引起的。